We expected Arsenal to learn from their previous mistakes after finishing second in the league for two seasons in a row, but the squad was not ready to take their opportunities last season when Manchester City, who normally dominate the league, were not in top form. Liverpool won the league title this season with 84 points, but it wasn't enough for the league dominating team. Arsenal did not play to their full strength, otherwise, last season may have been their best chance to win the title. If Manchester City were in top form, I doubt they would win the league with 84 points.
However, predicting what will happen next season will be tough because every team is active in the market, signing top players who can improve their performance the next season. If Manchester City can return to winning ways at the start of the next season, it will be difficult for Arsenal or Liverpool to win the league, however, if Manchester City performance remains as poor as it was last season, Arsenal may be able to win the league if they can compete throughout the season.
I personally believe that the way of promotion has started when we start learning from our mistakes. But keep ignoring the mistakes that will lead you to the failure. Arsenal's need is to learn from their mistakes last season and try to overcome them for the most wanting results. However, it is impossible to say before the next winner of next season. Anything would happen as every club seems very active and also in the race of selling and buying the players. So, for now every club is unpredictable but Manchester city is strongest among all. If they perform their best then the chances of winning could be difficult for remaining clubs. But it's only a hypothesis not to be a final verdict. Manchester city also needs to improve their performance only in case their chances are alive.